50 THE PHOSPHORESCENT ORGANS 



above and below, there are several thin, broad patches of 

 pigment. The spicular layer thins out ventrally, but ex- 

 tends a short distance beyond the lens. The ends of the 

 spicular layer are slightly turned up, though not nearly so 

 much so as the dorsal side. 



The gastric row has organs (fig. 6) very similar to those 

 of the upper opercular. The spicular layer forms a pocket 

 with the bottom at the dorsal side, and the ends are turned 

 up. But there is not so much material in the capsule, and 

 the lens is flatter. There is no pigment. The fibrous 

 connective tissue over the organ is comparatively thick. 

 The blood-vessel enters at the ventral side. 



The pleural organs (fig. 5) resemble the gastric, but 

 the spicular layer does not form so deep a pocket. The 

 spicular layer extends half the width of the organ below it 

 (ventrally). The lens is flatter, and the capsule is thin- 

 ner on all sides of the lens, than in the gastric organs. 

 There are masses of pigment at the dorsal side of the spic- 

 ular pocket, and flakes above and below it. The blood- 

 vessel enters at the ventral side. 



The large organs of the lateral row, with the exception 

 of having the spicular pocket a little deeper, are similar 

 to the pleural. 



The small organs are exactly like the frontal organs. 



The ventral organs are like the outer anal, except that 

 the spicular layer forms a little deeper cup, and the fibrous 

 connective tissue over the organ is thicker. 



Though sections of them were not cut, yet, judging from 

 the external appearances, it may be safe to conclude that 

 the dorsal and occipital organs are like the frontal, those 

 on the sides of the head like the upper opercular, and those 

 on the throat like the outer anal. 



As will be seen by the foregoing, these organs, though 

 varying much among themselves, are formed upon one gen- 



